17 May 2007

July-August 2006

Israeli scientists have been invited to present important new research on "double asteroids" at a US National Aeronautics and Space Administration workshop in Colorado.

The paper, to be presented this week by Tel Aviv University researchers at the "NEO [Near-Earth Object] Detection and Threat Mitigation" workshop, discusses the discovery of a high incidence of double "Aten-type" asteroids and the danger of their potential collision with Earth.

TAU runs a national information center (supported by the Israel Space Agency and the Science and Technology Ministry) on near-Earth asteroids and comets that are liable to cause our planet harm. At the TAU Wise Observatory in Mitzpe Ramon, researchers monitor these celestial bodies and study the light coming from them.

As part of his doctoral work at TAU, David Polishook investigated Aten-type asteroids that transverse the Earth's orbit but most of the time are located between the Earth and the Sun so that they are difficult to observe.

Out of eight bodies investigated, five were found to be double - a main asteroid several kilometers in diameter and a smaller "moon" that revolves around it. These moons are apparently several hundred meters in diameter and located only a few kilometers from the asteroids they circle.

This discovery is important because the presence of the moon disrupts scientists' plans of eliminating the danger to Earth posed by double asteroids either by changing their orbit or destroying them in a nuclear explosion.

Following the presentation on the discovery by TAU researchers, NASA workshop organizers are to write a report for the US Congress on the subject. Since only American citizens are permitted to present their research in person, the Israeli scientists were asked to send their data as a "white paper" for discussion.

A Kiowa County man said he may have found what could be one of the largest meteorites ever reported.

Don Stimpson said he and Paul Ross were searching Ross' field recently with a giant metal detector when the device made so much noise they thought they'd found an old culvert. Instead, they began digging up pieces of meteorite. "We dug and dug and brought up a 250-pound meteorite," said Stimpson, who had thought the field had been cleared of meteorites. "And then we looked, and there was another one there. We dug it out and...well, wait a minute, there is more. We brought 1,500 pounds of meteorite from that one hole."

Experts said the find may be part of the Brenham meteorites, a collection of space rocks that fell to Earth in the present-day Brenham Township near Haviland about 20,000 years ago.

Many are among the most famous and sought-after in the world because they are pallasites. The extremely rare rocks contain crystals that look like stained glass when they are cut.

Wichita State University physics professor David Alexander, whose specialty is astronomy, said that if the pieces Stimpson and Ross found are from one meteorite, it would be the largest pallasite ever found.

Professional meteorite hunter Steve Arnold found the current record-holder, a 1,400-pound pallasite, about two miles southeast of Ross' land last fall.

Stimpson said he's still excavating the crater, which he said is covered in a thick layer of rust about 20 feet in diameter. "We do not know how far it extends," he said. "I'll keep working on the site as long as I can and submit a scientific paper with my data when we are finished."

Meanwhile, the public can get a glimpse Saturday at what Stimpson and Ross found during Haviland's annual meteorite festival.

A planetary "all clear" sounded late Sun day night. A potentially hostile celestial visitor - a half-mile wide ball of primordial minerals named 2004 XP14 - whipped past our blue island on its way to what we all should hope is an eternal journey.

We should hope the journey is eternal, because if it stops here, so, most likely, would much of what we consider to be civilization.

Consider: Meteor Crater, the Arizona landmark many people visualize when they think of an asteroid impact, was the result of a relative interplanetary pebble. That chasm, nearly a mile across and more than 500 feet deep, was the result of impact by a space rock only about 80 feet in diameter.

But the Apollo-class asteroids - those whose solar orbits, like that of our most recent unwelcome guest, take them across the orbit of Earth - include far larger threats. Like the three-mile rock that blasted the 62-mile-wide Manicouagan impact structure in Quebec more than 200 million years ago - one of the largest impact craters still visible on the planet's surface. Or the six-mile space bomb believed to have eradicated the dinosaurs 100 million years later.

Scientists tell us that such truly catastrophic hits come every 100 million years or so, which makes us roughly due, the way such things are measured. But not to worry, they say; as far as they can observe and predict, nothing really nasty is headed our way. Of course, the length of that view is the cosmic equivalent of an eye's wink. We know of some 150 Apollo objects up to five miles across. It's likely that there are thousands we haven't tagged yet.

When the one with our name on it comes, they say, we'll know it - for a moment, at least. A land hit would obliterate thousands of square miles, followed by 13-magnitude earthquakes, volcanic eruptions and dust clouds that would blot out the sun for months. An ocean hit would produce mega-tsunamis up to three miles high, not only eradicating coastal life, but flooding the interiors of continents as well. The atmospheric steam cloud would alternatively turn Earth into an equatorial hothouse, then an icebox.

No, we would not survive as a civilization, most likely not as a species. That's why those who watch for and plot the orbits of these doomsday rocks are doing such important work. And why those who dream of thwarting the cataclysm dream such important dreams.

ELLISON BAY - A whistling noise and two "booms," like a bomb, woke Jim Quan out of sound sleep early Monday morning.

He got up and looked out the window of Linden Gallery and across Wisconsin 42 to see one building burning and two severely damaged.

"It sounded like bombs going off," said Quan.

He was visiting from his home in Burlingame, Calif., and was staying with his daughter, Jeanee, and her husband, Brian Linden, who own the Asian art gallery.

The blast broke windows at the gallery and at several other businesses and homes in Ellison Bay, an unincorporated hamlet in Liberty Grove at the tip of the Door County peninsula.

Across the highway, three girls - ages 12, 15 and 16 - awoke at the Cedar Grove Resort to find the building collapsing around them. The girls were up to their shoulders in burning insulation. Their story was interrupted by an adult who did not want them talking to the news media.

The girls were among 49 guests at the resort. All the guests were accounted for during the investigation of the incident.

Two people died in the explosion and fire that remain under investigation by the Wisconsin State Fire Marshal, Door County Sheriff's Department and Sister Bay/Liberty Grove Fire Department. The fire department was dispatched to the scene at 2:35 a.m. Monday.

The focus of the investigation was the condominiums at Cedar Grove and the adjacent Pioneer Store, a landmark Ellison Bay building flattened by the explosion.

The identities of the dead were not released pending notification of relatives.

Both bodies were recovered by mid-morning Monday and taken to the Brown County Medical Examiner's office in Green Bay for autopsies.

The girls and other people displaced by the explosion and fire were given food and shelter at the Ellison Bay fire station, one of two operated by the Sister Bay/Liberty Grove Fire Department.

onathan Bastian, a bartender at the Mink River Basin Supper Club in Ellison Bay, said he was finishing up for the night when he heard explosions and called 911. "I told them I think half the ... town blew up," he said. Four people were hospitalized in Green Bay and three others were released, Hecht said. Five others refused treatment or sought medical help on their own, he said.

Witnesses reported up to three blasts. Investigators were trying to determine whether one explosion or multiple blasts occurred, Hecht said. ?The first one woke me up,? said Laura Capp, 19, of Beach Park, Ill., who was sleeping in her family?s summer home about a quarter-mile away. ?The second one was really loud. The third one was quieter, really small,? she said, indicating the explosions happened a second or two apart. The explosions traveled like shock waves for almost a city block, neighboring residents said

STAVANGER, Norway -- A meteorite weighing about 4 pounds landed in western Norway during the weekend -- the second meteoritic impact in Norway within a month.

The meteorite, creating a crater about 10 inches deep, landed Sunday in the yard of a home, but caused no injuries or damage.

University of Stavanger Professor Per Amund Amundsen, a member of the Stavanger Astronomy Society, told Aftenposten meteorites land in Norway as often as every month, but most are never found. He called the incident 'extremely exciting.'

The meteorite might a valuable sales object, Aftenposten said, noting prices on the Internet for other meteorites ranged to more than $100,000.

Bill Waddell heard the whump of the object's arrival. He turned, stared at the strange fragment, and then called his golf buddies over for a look.

"You know," he told them, "there's a big chunk of metal there.

"It didn't come far from hitting me."

Later, all five men who were there would tell the same story of what happened Tuesday afternoon. The sky was clear blue. Not an airplane in sight. Nothing that could have lost a piece as it flew over Carson's Victoria Golf Course.

And yet there, lying in the clipped grass near the 17th hole, was a heavy chunk of metal too hot to touch.

"I really think this came out of orbit," offered Warren Straley, a member of the fivesome and a resident of Manhattan Beach. He once worked as a chief scientist for Hughes Aircraft.

"You know," he added, "there's tons of scrap metal up there."

The object, a solid square of metal with a hexagonal depression in the center and a hole punched through it, measures about 2.5 inches on each side. It weighs almost 2 pounds.

It has been bashed, blunted, scuffed and scarred. Most of it has been burnished to a rock-like dullness, but there are gashes that cut across its surface and lay bare a bright, silvery metal. Raised letters just visible on one side look like two C's.

The sudden arrival of the strange object interrupted the weekly outing of the senior men's golf club of Rolling Hills Covenant Church. The five retirees who gathered around it as it lay in the grass all guessed it came from the sky.

"My first thought was, this had to be a piece of space junk," one of them, Dave Nichols of Torrance, said later.

"It came down hard," said Mac Mc-Cardle, who also lives in Torrance.

"We were just glad that nobody was killed," said Robert Daligney of San Pedro. "It wouldn't even have to hit him in the head."

But while the object may have dropped out of a clear, blue sky, it probably didn't have all that far to drop. Some of its characteristics suggest it had an origin much closer to home than outer space, said Bill Ailor, director of the Center for Orbital and Re-entry Debris Studies at The Aerospace Corporation in El Segundo.

For one thing, it's too heavy. Spacecraft favor lighter materials that are easier and less costly to launch, Ailor said.

Then there are the scratches and machine marks. An object plunging through the atmosphere undergoes more than enough heat to melt steel, leaving it -- if it survives -- much smoother than the chunk that hit the golf course.

Still, Ailor said, objects that seem at first to have come from the heavens often have stories to tell, even when their origins turn out to be entirely terrestrial. Not long ago, a hot piece of metal crashed into a New York apartment. Investigators finally determined it was the overheated brake shoe of a big truck that had blown off.

Ailor reviewed a photograph of the chunk from the golf course. Asked to guess its origins, he said: "It looks like something that came off a heavy truck."

Whatever it is, the object was too hot to pick up when the golfers found it. They had to let it cool in the grass for 10 minutes before they could balance it on a golf ball and carry it to their carts.

And then they finished their round.

"As a matter of fact, that next hole was a mess," said Waddell, who lives on the Palos Verdes Peninsula and came a few feet from getting hit by the object.

"But I don't blame it on that," he added. "The 18th hole was all right."

The U.S. Air Force Space Command, which tracks space movement over North America, said today there has not been a man-made object flying over the Edmonton and northern Alberta region since at least Tuesday.

So that rules out the possibility that a bright fireball seen over Edmonton in broad daylight was that kind of man-made object.

A number of Edmontonians spotted a bright fireball low in the sky while driving northbound Wednesday shortly after 1 p.m.

Witnesses described the bright streak with a bit of a tail using a number of colours, including blue, white, green, pink and orange. It lasted a few second before disappearing.

Bruce McCurdy, an astronomer at the Telus World of Science, received a few calls about the object Wednesday, confirming that there was something in the sky.

When told it wasn't a man-made object, McCurdy said the fireball was probably "interplanetary debris" as he initially suspected.

Seeing a fireball during the day, McCurdy said, is very rare occurrence.

AMMAN - A group of local and international scientists have discovered a huge crater in the eastern part of the country caused by a gigantic meteorite, thought to be the largest such find in the region.

The impact site in Jabal Waqf es Swwan, some 200 kilometres east of the Karak Governorate close to the Saudi border, was discovered by University of Jordan geology professors Elias Salameh and Hani Khoury, along with German professor Werner Schneider.

According to Salameh, the meteorite struck the area around 7,500-10,000 years ago with an impact diameter of about 100 metres.

"The damage force of such an impact might equal 5,000 times that of the Hiroshima atomic bomb," according to Salameh, adding that it would have destroyed everything within a radius of hundreds of kilometres.

The crater consists of two concentric circles. The diameter of the outer ring measures around 5.5km, with the inner ring measuring 2.7km.

The impact size and velocity, according to Salameh, would have raised the atmospheric temperature within a radius of 10 kilometres to more than one thousand degrees centigrade, spewing millions of tonnes of rocks, vapour, dust and smoke into the atmosphere.

This in turn would have formed an atmospheric cloud so large as to plunge the entire earth into darkness, with continuous rain for months or even years, resulting in the widespread flooding of low lands, according to a statement by the University of Jordan.

The discovery is thought to be the largest such meteorite crater in the region.

Future research at the site, which has been well-preserved due to the area's dry climate, will be supported by the University of Jordan and the Higher Council for Science and Technology.

Highlighting the importance of the find, Salameh said the site is expected to explain many geologic and historic features and events such as calcinated rocks, molten rock, highly jointed and cracked rocks.

There are around 130 crater structures of impact origin in the world. One of the oldest and largest clearly visible sites is the Vredefort Dome, located in South Africa.

The original crater, now eroded, was probably 250 to 300 kilometres in diameter, larger than the Sudbury impact structure in Canada, about 200km in diameter.

At two billion years old, Vredefort is far older than the Chixculub structure in Mexico which, with an age of 65 million years, is the site of the impact that is said to have led to the extinction of the dinosaurs.

All relevant institutions in Jordan have been informed about the discovery, including the Badia Project, the Department of Lands and Survey and the Natural Resources Authority, in order to take the necessary steps to conserve the site.

MISSOURI CITY, TX - There's a bizarre mystery in Fort Bend County. A strange piece of metal fell right out of the sky, just missing a Missouri City woman.

Lynn Moore was parked at a convenience store at the intersection of US 90 and Pitts Road last Thursday when the object came crashing down.

There are two small holes in the piece of metal. Moore thinks it was once bolted to something. She says the object hit her van and a truck parked next to her.

Fort Bend County sheriff's deputies filed a report, but there's no word yet what the object might be.

You may remember back in June, a strange metal object fell out of the sky in Porter and hit the hat a man was wearing while standing in his garden. Amazingly, he wasn't hurt. The homeowner lives just a few miles away from Bush Intercontinental Airport. There were no identifying marks on the object, but aviation experts agreed it looked like something from a small airplane.

A spectacular meteor shower might be in the offing late next summer, SPACE.com has learned.

It may not last very long, but could produce a bevy of bright, swift shooting stars for favorably positioned skywatchers. The prediction is found in a technical report, co-authored by two astronomers who are targeting Sept. 1, 2007 as the date for the potential display.

The meteors are called "Aurigids" because they appear to fan-out from the constellation of Auriga, the Charioteer.

At least a strong shower

Meteor showers occur whenever we ride into the dusty debris left behind in a comet's orbit. The debris left behind by Kiess, a comet last seen in 1911, is what produces the Aurigids. The comet takes approximately 2,500 years to orbit the Sun, but there are also dense trails of dust traveling along its orbit. Earth has had glancing blows in the past with a few of these dust trails in 1935, 1986 and 1994.

In 2007, however, the Earth is expected to pass very close to the center of a dust trail, which astronomers Esko Lyytinen of Finland and Peter Jenniskens of NASA's SETI Institute in California said, should result in "a spectacularly rich shower of bright meteors."

The researchers in the past used computer models to predict outbursts of the Leonid meteor shower, which wowed skywatchers in 2001 and 2002.

Shooting stars, or meteors, are common any night of the year; five or six per hour are normal. During a respectable meteor shower, they can be seen streaking across the sky every few minutes. But occasionally the sky explodes in a shower of sparks, a rare meteor "storm" that is something to get excited about.

Meteor storm possible?

No one is certain how strong next year's Aurigids may be, but tomorrow, Jenniskens will make an announcement at the General Assembly of the International Astronomical Union in Prague concerning an "Aurigid Meteor Storm" of Sept. 1, 2007.

Meteor storms are typically said to involve at least 1,000 meteors per hour, a rate sometimes achieved only in 15-minute bursts. It is not clear what sort of hourly rate Jenniskens will announce as his prediction, however.

"I do not know why Peter Jenniskens will announce this as a storm," Lyytinen told SPACE.com. "I have not especially tried to predict the strength but I would guess only a good or moderate shower, a storm not impossible."

The peak of the shower is predicted to occur at 11:37 GMT. Unfortunately this comes during daylight for Europe and much of North America. But the western United States and Canada, as well as much of Alaska and Hawaii will still be in pre-dawn darkness and would be in an excellent position to view it.

Another drawback will be a gibbous Moon, four days past full, whose light could interfere with observing. But, Lytinnen said, many of the meteors are expected to be very bright. "So, maybe the moon does not make very much harm in the observations ... I hope."

PRAGUE, Czech Republic - They're out there, hidden among a haze of stars - killer asteroids. Now the world's astronomers are keeping a wary eye to the skies for giant objects on a collison course with Earth.

Experts say there are about 1,100 comets and asteroids in the inner solar system that are at least a half-mile across, and that any one of them could unleash a global cataclysm capable of killing millions in a single blinding flash.

On Thursday, the International Astronomical Union said it has set up a special task force to sharpen its focus on threats from such "near-Earth objects."

"The goal is to discover these killer asteroids before they discover us," said Nick Kaiser of the University of Hawaii's Institute for Astronomy, which hopes to train four powerful digital cameras on the heavens to watch for would-be intruders.

There are no asteroid busters to stop one right now, but scientists believe that one day a defense could be devised, such as using spacecraft to divert a killer comet.

Congress has asked NASA for a plan to comb the cosmos for even smaller, more distant objects, including asteroids just 1 1/2 football fields across. The space agency is to catalog their position, speed and course by 2020. Already, there are 103 objects on an "impact risk" watch list.

Scientists warn there are as many as 100,000 of these "smaller" heavenly bodies with the potential to take out entire cities or set off a tsunami like the killer wave that swept through the Indian Ocean in December 2004.

Earth's craters bear silent witness to what can happen even when a smallish asteroid slams home. In 1908, one struck remote central Siberia, unleashing as much energy as a 15-megaton nuclear bomb. Fortunately, it wiped out 60 million trees, not people. Had it hit a populated area, the loss of life would have been staggering.

There's some recent good news too: Earth's most pressing threat - the asteroid 99942 Apophis - appears to have eased. Scientists initially gave it a 1-in-5,500 chance of hitting the planet in 2036, with enough power to wipe out the New York City metro area. But experts said Thursday the latest observations suggest those odds have dwindled to 1-in-30,000.

They won't be sure until it makes an earlier pass in 2029, when it's expected to come within 18,640 miles of Earth. If that sounds comfortably distant, consider this: It's closer than many commercial satellites and a good deal nearer than the moon.

Although close encounters are unnerving, they give astronomers a unique opportunity to get a better glimpse of asteroids and comets - the leftover building materials of the universe - and gain a better understanding of the origins of the solar system.

Scientists say expanding their database of the objects crowding Earth's neighborhood could help produce a permanent warning system like those that now monitor the Pacific for tsunamis or keep tabs on volcanoes and earthquake zones.

Give the world a decade or so of lead time to deal with a specific threat, they say, and it stands a chance of getting out of harm's way - perhaps by sending up a spacecraft to nudge an asteroid off-course.

"Right now, unfortunately, there are no 'asteroid busters' or hot lines. Who ya gonna call?" said Andrea Milani Comparetti, a professor of mathematics at Italy's University of Pisa.

To be on the safe side, astronomers trying to determine the odds of one hitting Earth work with computer models that surround it with thousands of "virtual asteroids." Experts then map out the likely orbits for each one and factor those in to come up with the probability of an impact.

But widening the search for threatening objects creates a problem: Discoveries could become commonplace, either creating unnecessary panic and confusion or lulling the public into a false sense of complacency.

"We're now going to be finding such objects once a week instead of once a year," said David Morrison, a NASA scientist who will chair the new task force.

"Only in Hollywood do asteroids arbitrarily change orbits," he said. "But there is great potential for misunderstanding. Dealing with probability and risk is a problem for all of us, whether we're dealing with asteroid impacts or terrorist attacks."

Bottom line: Mankind may not be able to dodge every cosmic bullet.

"It's through collisions that planets are born," said Giovanni Valsecchi of Italy's National Institute of Astrophysics. "And it's through collisions that planets die."

HILO - The FBI and the Transportation Security Administration are investigating sightings of an object resembling a missile flying over the Hilo Airport area Tuesday morning, Hawaii County Civil Defense said.

Reports gave opposite descriptions of its direction and widely varying estimates of its size.

The largest estimate was about 12 feet long, and the smallest was one foot. One report said it was headed over the airport's main runway, but another said it was headed north from Hilo, away from the airport.

Civil Defense official Lanny Nakano said the federal agencies classified the sighting as unconfirmed. The FBI and TSA did not return requests for comment.

Nakano, reading from notes from another Civil Defense official, said it was seen at 10:18 a.m. headed away from the airport.

But an eyewitness, who asked that his name not be used, told the Star-Bulletin he saw it heading from the Civic Auditorium area to the Keaukaha area, which would take it over the main runway.

That witness saw a silver tube with no markings or fins, trailing "vapor" that quickly dispersed.

"The noise was super-loud," he said.

Police also interviewed about a half-dozen witnesses who saw or heard it, said police spokeswoman Chris Loos.

Loos and the nameless witness said there were plane flights before and after the object was sighted, but the object did not appear connected to their presence.

At Pohakuloa Training Area, 30 miles to the west, spokesman Bob McElroy said there were no military exercises using missiles.

"It was colored white, green and gold, and lights seemed to blow off it like it was a sparkler," said one observer, Andre Gr?nmo. "It looked like it was a comet, and it was around four- to five times larger than a plane, and it flew much faster."

Several police districts logged reports from members of the public who observed "something" flying at high speed.

"What they're talking about here is some sort of flying object, and we can't explain what it was," Oddgeir Slettli, operations leader for the Midtre H?logaland Police District, told dagbladet.no.

Observations were reported from Finnsnes to Trondheim. The main search and rescue station in northern Norway (Hovedredningssentralen Nord-Norge) reported that calls also came from crews on board ships off the northern coast, according to Dagbladet.

"It was colored white, green and gold, and lights seemed to blow off it like it was a sparkler," said one observer, Andre Gr?nmo. "It looked like it was a comet, and it was around four- to five times larger than a plane, and it flew much faster."

Slettli said others described a "green, lighted ball with a tail" that flew low. He said neither the Defense Department's radar station or its rocket facility at And?ya, nor the tower at Evenes airport, which serves Harstad and Narvik, had picked up the object.Slettli said calls came from people in Narvik, Vester?len and Lofoten among other places, just before midnight on Monday.

A flurry of reports also came over the Coast Guard radio, and from an SAS flight and a Hurtigruten (Coastal Voyage) passenger ship.

Knut J?rge R?ed ?degaard, one of Norway's most well-known astronomers, said he thinks the UFO was actually another meteorite, a large rock containing a lot of chemical elements. There have been confirmed reports of at least two meteorites hitting Norway since June.

"When they enter the earth's atmosphere and meet the air, they warm up and can light up in a second," he told dagbladet.no.

This one's contents, the astronomer said, could explain why it seemed to change color as it flew through the night sky, which only recently has started getting dark again after the summer's midnight sun.

If you are tired of thinking about global warming, terrorist attacks or contracting a deadly new virus, maybe you could get out of your rut by mulling over the possibility that some large celestial body may be on a collision course with our planet.

Last month, the asteroid 2004 XP14 passed some 268,873 miles (432,000 kilometers) from Earth. That distance is slightly greater than that between the Earth and the moon.

Astronomers called it "a close shave in the vastness of outer space."

If a collision had occurred, the memory of the Fourth of July fireworks would be dimmed. Pig Out in the Park would have to be canceled for a couple thousand years.

Scientists say that a fatal cosmic concussion probably will come from a giant chunk of rock like 2004 XP14 - one of the many that jump from the asteroid belt under the evil influence of Jupiter - or a comet returning to our solar system. That comet would show up as a stationary but growing dot of light in the night sky.

It would appear stationary because it would be coming straight at us.

Although total planetary destruction is still total planetary destruction, death by comet might be preferable to death by meteor.

The first advantage of a comet impact is that astronomers would be able to give us more time to prepare for extinction. You would not have time to read a thick novel, go on a diet, work a 12-step program or even play an extended game of Monopoly, but you would have time for a frank no-holds-barred talk with your in-laws or to unload some bottled-up grievances to your boss.

A comet also would provide several days of spectacular visual effects with its fluffy ice and vapors streaming behind.

On the other hand, a typical giant meteor would provide nothing to look at until it flamed up for a few scant seconds prior to the explosion that would wipe us all out.

Another reason that we earthlings might prefer oblivion by comet is that the meteor strike has been done before.

Scientists say that dust from a meteor hit filled the air back in 65 million B.C. Most life on Earth was wiped out.

Scientists know this because buried in the Earth at the 65 million year depth is a layer of iridium, a nonbiodegradable element that is relatively rare on Earth but a common component of meteors.

Dinosaur fossils are found below that iridium layer while mammal bones are found above. If we take another big hit, our only comfort is that a life form higher than humans may evolve above our own bones.

Then, like the dinosaurs, we'll be gone but not forgotten forever; after a few million years our successors (the new life forms) will dig up our bones and display them standing naked in their museums with a sign that says, "They didn't know what hit them."

There probably will be scary movies made about us, and they are sure to make disparaging remarks about our tiny brains.

If you want to be "in-the-know" before the Earth is obliterated, go to the Spokane Astronomical Society's Web site, spokaneastronomical.org. The group has lots of free information, and it holds "star parties" where members provide powerful telescopes, free to the public, so you might get a look at the celestial threats that currently are heading our way.

A meteor lit up the Hawke's Bay sky last night and burned up with a boom that rattled windows.

"It was like an earthquake, but without the shaking," said one Akina woman.

Maraekakaho woman Liz Wilson heard "the weirdest noise, like a V8 engine" at about 9.45pm.

"We got in the car, as you do, and had a look around the place ... we so wanted to find a big, burning thing," she said.

An Otane woman said her father saw a "huge, big fireball with a long tail" overhead and heading towards Elsthorpe.

Bruce Hoyt was driving south along the Hawke's Bay Expressway when the sky lit up as if by lightning.

"It came down, heading south, then broke up into six to eight pieces, before fading out. A second or so later, I heard a bang.

"I would say the bang was from the meteor hitting the atmosphere. The sound came later because it travels slower than light."

That summation was right, said Hawke's Bay Astronomical Society president Gary Sparks. "When these things come in, it is explosive decompression. With the heat of re-entry they reach a critical temperature and they explode," he said.

The clear sky last night would have helped the sound travel. His guess was the meteor would have been no larger than a basketball.

August is one of the times of year when meteor showers were more frequent, Mr Sparks said, with the Earth - orbiting the Sun at 100,000km/h - meeting the dust trail of a meteor.

"What people saw last night was probably a rogue meteor, something that was not in the same path as the dust trail," Mr Sparks said.

The scientist reports that the TCB was a comet, containing organic matter, which was heated after entering Earth's atmosphere, and organic matter started decomposing intensively and emitting carbon dioxide.

The scientist also showed the results of chemical analysis of particles found in wood and soil - their composition reminded that of the Halley's comet, studied by means of "Vega" spaceship.

The scientists are still unable to perform total identification of the TCB chemical composition, but they are sure that some high-temperature process (an explosion) had definitely taken place.